结构体的排序，定义一个5个元素的 struct STUDENT 数组，

（1）从键盘输入5个学生的信息。

（2）按总分降序排序。

（3）按语文成绩降序排序。

（4）按姓名升序排序。-Structure of the sort, define a five-element array of struct STUDENT, (1) from the keyboard 5 student information. (2) in descending order by total score. (3) results in descending order by language. (4) by name in ascending order.